Change of direction (COD) is an important component of all most all team and field sports. Consequently, it is often a late progression in rehab programmes for physiotherapists and physical therapists. Change of direction drills range from sharp turns at high speed to curved turns at slower speeds and everything in between!
Most physios normally have the following questions regarding where to start their change of direction or agility rehabilitation:
· Which drills are safe for my patient at this stage ?
· Which one is most effective at this stage ?
So where do you start?
There is a multitude of change of direction drills that can be chosen for any particular sport or movement impairment. We all want to make reasoned and evidence informed decsions. To make informed decisions we all need frameworks which we can hang our hats on. All too often agility and change of direction drills are chosen based upon the preference of the therapist or some other arbitrary marker.
Well there is a solution!
The angle of entry into the change of direction drill is a sensible and evidence informed framework to progress a rehabilitation programme for a patient.
In simple terms the sharper the angle of the cut (or more extreme the angle upon entry) for the change of direction task the higher the following:
1. Higher muscle breaking forces to decelerate the patient E.g. (Higher eccentric muscle loading)
2. Higher ground contact times E.g. (Higher ground impact forces)
3. Higher knee joint loading forces
4. Higher muscle reacceleration forces E.g. (Higher concentric muscle loading)
The change of direction angles that have receive the most attention in the literature and are most relevant to your practice are the following:
1. 45 degree cut
2. 90 degree cut
3. 180 degree cut
These angles have consistently been shown to progressively increase knee joint loading and muscle breaking forces from the 45 degree angle all the way up to the 180-degree angle.
What are the clinical implications for your rehabilitation progressions ?
Well, this is a very nice evidence base progression criteria that can be adapted for the rehabilitation of change of direction ability. It is logical and very easy to understand for you and your patients.
So what do we know?
We know that eccentric muscle forces (breaking forces ) are significantly greater in a 90-degree change of direction (COD) task when compared to a 45-degree COD task. Also we know that ground reaction forces and knee joint reaction forces are also significantly greater in a 90 degree and above COD task compared to a 45-degree task in male and female team sports players. It has also been shown that ground contact times (i.e. how much time is spent on the ground) is higher in a 90-degree cut compared to a 45-degree cut.
So to summrise that last paragraph…… It means that when a patient is asked to do a 90-degree or above change of direction task the lower limb loading is much higher than a 45 degree COD task.
How do I use this in my rehab? The traffic light system
This means that it is probably not wise to start a patients COD rehabilitation with high entry angles because of the significant forces involved. It is therefore sensible to start well below the 45 degree threshold with softer curved entries to the change of direction task . As the patients technique, muscle strength and physical capacity improves a gradual progression towards 60- 90 degree tasks becomes safer. As you move the patient towards the later stages of rehabilitation and return to sport higher angle drills at 45- 90 degrees and then up to 180 degree cutting drills can be incorporated.
This allows a safe progression for your patient because of the reduced breaking forces and knee joint loading at low angles of entry. Also this provides a very nice method for the progressive loading of the knee joint in a sequential manner.
This probably has implications for other lower limb joints such as the ankle and hip, because logically they will also be subject to similar loading forces during their recover after injury.
So, this traffic light system hopefully provides you will a sensible framework for prescribing change of direction drills for your patients recovering after lower limb injury.
Further reading
Biomechanical Determinants of Knee Joint Loads Associated with Increased Anterior Cruciate Ligament Loading During Cutting: A Systematic Review and Technical Framework—PubMed. (n.d.). Retrieved 23 July 2021, from https://pubmed.ncbi.nlm.nih.gov/33136207/
Dos’Santos, T., McBurnie, A., Thomas, C., Comfort, P., & Jones, P. A. (2020). Biomechanical Determinants of the Modified and Traditional 505 Change of Direction Speed Test. Journal of Strength and Conditioning Research, 34(5), 1285–1296. https://doi.org/10.1519/JSC.0000000000003439
Dos’Santos, T., Thomas, C., Comfort, P., & Jones, P. A. (2018). The Effect of Angle and Velocity on Change of Direction Biomechanics: An Angle-Velocity Trade-Off. Sports Medicine (Auckland, N.Z.), 48(10), 2235–2253. https://doi.org/10.1007/s40279-018-0968-3
Dos’Santos, T., Thomas, C., McBurnie, A., Comfort, P., & Jones, P. A. (2021a). Biomechanical Determinants of Performance and Injury Risk During Cutting: A Performance-Injury Conflict? Sports Medicine (Auckland, N.Z.). https://doi.org/10.1007/s40279-021-01448-3
Hammami, A., Gabbett, T. J., Slimani, M., & Bouhlel, E. (2018). Does small-sided games training improve physical fitness and team-sport-specific skills? A systematic review and meta-analysis. The Journal of Sports Medicine and Physical Fitness, 58(10), 1446–1455. https://doi.org/10.23736/S0022-4707.17.07420-5
McBurnie, A. J., DosʼSantos, T., & Jones, P. A. (2019). Biomechanical Associates of Performance and Knee Joint Loads During A 70-90° Cutting Maneuver in Subelite Soccer Players. Journal of Strength and Conditioning Research. https://doi.org/10.1519/JSC.0000000000003252
Paul, D. J., Gabbett, T. J., & Nassis, G. P. (2016). Agility in Team Sports: Testing, Training and Factors Affecting Performance. Sports Medicine (Auckland, N.Z.), 46(3), 421–442. https://doi.org/10.1007/s40279-015-0428-2
Santoro, E., Tessitore, A., Liu, C., Chen, C.-H., Khemtong, C., Mandorino, M., Lee, Y.-H., & Condello, G. (2021). The Biomechanical Characterization of the Turning Phase during a 180° Change of Direction. International Journal of Environmental Research and Public Health, 18, 5519. https://doi.org/10.3390/ijerph18115519
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